As Atmospheric Carbon Dioxide Reaches Milestone, Continued Inaction Could Spell Disaster for Our Oceans

Earlier this week, we reached a troubling milestone as carbon dioxide (CO₂) levels in the Arctic atmosphere exceeded 400 parts per million (ppm). 

Increased atmospheric CO₂ has a devastating effect on our ocean ecosystems. As the chief regulator of climate, the ocean acts as a “carbon sink,” absorbing more than a quarter of the CO₂ humans pump into the air. Increased CO₂ absorption results in a lower oceanic pH level, a phenomenon called “ocean acidification.” With a global average of 395 ppm, CO₂ levels have increased more than 140% since the Industrial Revolution. The ocean simply cannot keep up.

To learn more about the chemical process of ocean acidification, please click here.

Already, ocean acidification has had serious effects on organisms with calcified shells. As ocean acidity increases, the chemical building blocks for the shells of mollusks and skeletons of corals become less and less available. Consequently, reef structure becomes weaker, coral growth slows, and it becomes easier for disease and encrusting algae to gain a foothold, leading to mass bleachings and die-offs. Reefs are notoriously slow-growing and serve as vital nurseries to commercially and ecologically important fisheries, providing a haven for life in otherwise nutrient-poor water. Therefore, when combined with other stressors such as pollution, increased sedimentation, overfishing, bottom trawling, and a warming ocean, it becomes obvious that our oceans are in a very precarious position. 

Vibrant and healthy coral reef in the Virgin Islands. Photo courtesy of NOAA CCMA Biogeography Team.

 

Acropora corals in the Tumon Bay Marine Preserve in Guam after bleaching event in 2007. Photo credit: Dave Burdick, courtesy of NOAA.

What can be done to help alleviate the threats to our reefs posed by increased atmospheric CO₂? The response must be two-fold. We must create and maintain no-take marine reserves across the globe. Ecosystems that are healthy and not facing multiple assaults have a greater chance of adapting to the changing climate. Additionally, we must continue to monitor and research the effects of ocean acidification, which will help scientists and conservationists focus on the most vulnerable species and ecosystems.

To learn more about Marine Conservation Institute’s efforts to address this emerging threat, please look at our Ocean Acidification page

In 2009, Congress passed the Federal Ocean AcidificationResearch and Monitoring Act (FOARAM) which directed the National Oceanic and Atmospheric Administration (NOAA) to work in conjunction with the National Science Foundation (NSF) to study and monitor the effects and potential outcomes of ocean acidification as a direct result of rising atmospheric CO₂ levels. This was an encouraging first step to understanding and mitigating the effects of climate change on our ocean ecosystems. However, the continued increase in CO₂ emissions indicates that our leaders, albeit with a few exceptions, are failing to adequately address climate change. It is real and it is happening, with disastrous implications for the health of our oceans and, by extension, our planet. In this vitally important election year, continue to hold your elected officials accountable.